Paul Bibby

Sydney woman Kate Malonyay may have been murdered by her ex-boyfriend because she uncovered the web of lies he had concocted about his life and was sharing her discoveries with his family, a coronial inquest has revealed.

Deputy State Coroner Hugh Dillon formally confirmed on Friday what police and Ms Malonyay's family had strongly suspected for some time: that the bright, bubbly 32-year-old had been murdered by navy systems analyst Elliot Coulson in her Mosman bedroom between April 17 and 19 last year.

The coroner found that Ms Malonyay, found lying in her bed by police after friends expressed concern for her welfare, died from "a combination of asphyxia, probably from manual neck compression (ie, strangulation), and a head injury caused by blunt force, perhaps from some kind of edged implement or edged surface".

Murdered: Kate Malonyay. Photo: Police Media

He also confirmed disturbing police reports that, after murdering Ms Malonyay, Coulson had used the young woman's phone to fool her friends into thinking she was all right by sending fake text messages.

The coroner's findings reveal that, in the weeks leading up to her death, Ms Malonyay had learnt that much of what Coulson had told her about himself was lies, and had begun speaking to his family.

"Some of the lies related to his whereabouts, or overstating the amount of his salary, or the value of a gift or how important he was at work," Mr Dillon found.

"But others were quite bizarre.

"He falsely claimed that his father had a brain tumour, that his parents had booked first-class tickets for them for a holiday in Hawaii and, most strikingly, that he had had a twin brother who had died in a car accident. Kate even told friends that Coulson had taken her to the grave site of his dead brother and they had mourned together."

The coroner said it appeared Coulson became aware in early April 2013 that Ms Malonyay was "making inquiries about him and talking about his lies with his family".

On April 3, 2013, she reportedly sent a text message to Mr Coulson's sister that read "Elliott might be suss we've been in contact and treading carefully".

Coulson contacted the woman soon after, indicating that he wanted to meet up.

He murdered her less than two weeks later.

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